Preparation of microemulsions and nanoemulsions by membrane emulsification

This paper is an overview of the applications of microporous membranes for preparation of micro/nano- emulsions. Membrane emulsification offers compact devices for preparation of nanoemulsions with low energy consumption, tuneable droplet size, monomodal distribution, and high encapsulation efficiency of entrapped functional components without shear or thermal degradation. The properties and wettability modification of Shirasu Porous Glass (SPG) membrane, track-etched polymeric sheets, syringe filters, anodic alumina membrane, and nickel-based superalloy membranes were discussed, as well as the design and operation of membrane devices. Particular emphasis was placed on the effect of formulation, operating parameters, and membrane properties on the resulting droplet size in direct and premix membrane emulsification with the examples of nano-sized emulsions produced using different membranes. The application of microemulsions prepared using synthetic membranes for production of solid self-microemulsifying drug delivery systems for enhanced solubility and oral bioavailability of BSC Class II and III drugs was also reviewed, as well as production of solid nanoparticles such as nanogels, solid lipid nanoparticles, synthetic biodegradable polymer nanoparticles, silica and metal oxide nanoparticles from nanoemulsion templates prepared by membrane emulsification.